Setting
activation thresholds remains a challenge in functional MRI. While strategies
exist to address the increased chance of false positive activations due to
the large number of voxels in an fMRI image, these methods frequently ignore
differences in activation strength between tasks, individuals, and scanners.
Setting appropriate thresholds is particularly pertinent in presurgical
mapping, as knowledge of the location and extent of functional cortex can
affect surgical decisions. In this work, we demonstrate an automated
threshold technique based on test-retest imaging and receiver-operator
characteristic curves, which produces individualized threshold levels
optimized for reproducibility of the observed activation.